Heated Oxygen Sensor (Ho2S)

WARNING: This page is about a different car, the 1995 Ford Pickup, 1995 Ford Econoline, 1995 Ford Club Wagon, and 1995 Ford Bronco. However, it is still accessible from the selected car via links, so may be relevant.

Vehicle may be equipped with one or 2 HO2S sensors. They are located in exhaust pipe, upstream of catalytic converters. Faults in sensor or circuit should set a diagnostic trouble code. See QUICK TEST in TESTS W/CODES - EEC-IV (5.0L) article. If no diagnostic trouble code has been set, see CIRCUIT TEST H in the appropriate TESTS W/CODES - EEC-IV (5.0L) article for additional sensor specifications and circuit testing procedures. Ensure that none of following conditions exist:

Moisture inside sensor/harness connector.
HO2S sensor coated with contaminants.
Sensor circuit open or shorted to ground.